Telephone-transmitter



(No Model.)

J. B. SMITH, TELEPHONE TRANSMITTER.

No. 521,325. Patented June 12, 1894.

EEEES UNITED STATES PATENT OEEICE. r

JOSEPH BRODIE SMITH, OF MANCHESTER, NEW HAMPSHIRE.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 521,325, dated June 12,1894.

Application filed April 27, 18 94.

.To @ZZ whom t may concern.-

Be it known that I, JOSEPH BRODIE SMITH, a citizen of the United States,and a resident of Manchester, in the county of Hillsborough and State ofNew Hampshire, have inventedv new and useful Improvements in Telephone-Transmitters, of which the following, taken in connection with theaccompanying drawings, is a specification.

This invention relates to improvements in variable resistancetransmitters for telephones particularly adapted for long distance workand it is carried out as follows, reference being had to theaccompanying drawings, wherein- Figure 1,represents a top plan view oftheinvention showing the top end of the electrode containing cup asremoved. Fig. 2, ,represents a cross section on the line 2-2 shown inFig. 1. Fig. 3, represents a sectionalview of a modification of theinvention; and Fig. 4, represents a partial top plan view of Fig. 3.Fig. 5, represents an enlarged section like theone shown in Fig. 2; andFig. 6, represents a modification of the manner of supporting the lowercup on the sound receiving diaphragm. n

Similar letters refer to similar parts wherever they occur on thedierent parts of the drawings.

In the drawings A represents the sound receiving diaphragm supported andheld in a ring or frame B to the lower portion of which is secured orconnected the mouth piece C as usual in devices of this kind.

v Upon the diaphragm A is 'supported or connected thereto a cup D madeof insulating or conducting material which cup contains finely dividedconducting material E preferably carbon. f

In Figs. 2, 3 and 5 I have shown the cup D as connected to the diaphragmA by means of a fastening screw d and in Fig. 6 I have shown a suitableyielding spring or elastic cushion dinterposed between said cup D andthe diaphragm A and I Wish to state that I do not wish to confine myselfto any particular manner of supporting said cup on the diaphragm as thismay be done in either of the manners described that is connected to oryieldingly supported on said diaphragm without departing from theessence of my invention.

To the ring or frame B is connected in a suitable manner the electrodesupport vF 'purpose set forth.

Serial No. 509,199. (No model.)

which in Figs. 1, 2,iand 5 is shown as a rigid bar secured in avertically or nearly so adjustable manner to the ring or frame B. InFigs. 3 and 4 said electrode support Fis represented as a yieldingspring having means for adjusting it to and from the diaphragm as inFigs. 2 and 5 for the purpose of regulating from time to time thesensitiveness of the instrument.

To the under side of the support F is secured an invertedcup Gr ofinsulating material containing a multiple electrode composed of a seriesof layers H, H, H H insulated from each other by sheets of mica I I orother suitable insulating mediums as shown in the drawings. The lowerportion of said multiple electrode is in contact with the finely dividedconducting material E as shown. The alternate layers `H H are connectedtogether by means of a wire h and the corresponding alternate layers H Hare connected together by means of a wire h shown in Fig. 1 which wireslead respectively to the battery and primary of the induction coil asusual in telephone transmitters.

By vthe construction as above described the transmitted voice isincreased in loudness rendering the telephone very serviceable andpractical for long distance service.

What I wish to secure by Letters Patent and claim is 1. In a telephonetransmitter a multiple electrode made in sections the alternateinsulated layers of which are connected together combined with a cupcontaining finely divided conducting material supported on a diaphragmand adapted to vibrate in unison with the latter substantially as andfor the 2. In a telephone' transmitter a multiple ,electrode made insections the alternate infl sulated layers of which are connectedtogether and rigidly supported combined with a cup containing finelydivided conducting material supported on adiaphragm and adapted tovibrate in unison with the latter substantially as specified.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 13th day of April, A. D.1894. l

JOSEPH BRODIE SMITH. Witnesses:

ALBAN ANDEEN, KrrrIE M. HANsoN.

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